private static TagBuilder WrapInListItem(TagBuilder inner, PagedListRenderOptions options, params string[] classes)
{
var li = new TagBuilder("li");
foreach (var @class in classes)
li.AddCssClass(@class);
if (options.FunctionToTransformEachPageLink != null)
return options.FunctionToTransformEachPageLink(li, inner);
AppendHtml(li, TagBuilderToString(inner));
return li;
}
private static TagBuilder First(IPagedList list, Func<int, string> generatePageUrl, PagedListRenderOptions options)
{
const int targetPageNumber = 1;
var first = new TagBuilder("a");
AppendHtml(first, string.Format(options.LinkToFirstPageFormat, targetPageNumber));
foreach (var c in options.PageClasses ?? Enumerable.Empty<string>())
first.AddCssClass(c);
if (list.IsFirstPage)
return WrapInListItem(first, options, "PagedList-skipToFirst", "disabled");
first.Attributes["href"] = generatePageUrl(targetPageNumber);
return WrapInListItem(first, options, "PagedList-skipToFirst");
}
private static TagBuilder Previous(IPagedList list, Func<int, string> generatePageUrl, PagedListRenderOptions options)
{
var targetPageNumber = list.PageNumber - 1;
var previous = new TagBuilder("a");
AppendHtml(previous, string.Format(options.LinkToPreviousPageFormat, targetPageNumber));
previous.Attributes["rel"] = "prev";
foreach (var c in options.PageClasses ?? Enumerable.Empty<string>())
previous.AddCssClass(c);
if (!list.HasPreviousPage)
return WrapInListItem(previous, options, options.PreviousElementClass, "disabled");
previous.Attributes["href"] = generatePageUrl(targetPageNumber);
return WrapInListItem(previous, options, options.PreviousElementClass);
}
private static TagBuilder Page(int i, IPagedList list, Func<int, string> generatePageUrl, PagedListRenderOptions options)
{
var format = options.FunctionToDisplayEachPageNumber
?? (pageNumber => string.Format(options.LinkToIndividualPageFormat, pageNumber));
var targetPageNumber = i;
var page = i == list.PageNumber ? new TagBuilder("span") : new TagBuilder("a");
SetInnerText(page, format(targetPageNumber));
foreach (var c in options.PageClasses ?? Enumerable.Empty<string>())
page.AddCssClass(c);
if (i == list.PageNumber)
return WrapInListItem(page, options, options.ActiveLiElementClass);
page.Attributes["href"] = generatePageUrl(targetPageNumber);
return WrapInListItem(page, options);
}
///<summary>
/// Displays a configurable paging control for instances of PagedList.
///</summary>
///<param name = "html">This method is meant to hook off HtmlHelper as an extension method.</param>
///<param name = "list">The PagedList to use as the data source.</param>
///<param name = "generatePageUrl">A function that takes the page number of the desired page and returns a URL-string that will load that page.</param>
///<param name = "options">Formatting options.</param>
///<returns>Outputs the paging control HTML.</returns>
public static HtmlString PagedListPager(this System.Web.Mvc.HtmlHelper html,
IPagedList list,
Func<int, string> generatePageUrl,
PagedListRenderOptions options)
{
if (options.Display == PagedListDisplayMode.Never || (options.Display == PagedListDisplayMode.IfNeeded && list.PageCount <= 1))
return null;
var listItemLinks = new List<TagBuilder>();
//calculate start and end of range of page numbers
var firstPageToDisplay = 1;
var lastPageToDisplay = list.PageCount;
var pageNumbersToDisplay = lastPageToDisplay;
if (options.MaximumPageNumbersToDisplay.HasValue && list.PageCount > options.MaximumPageNumbersToDisplay)
{
// cannot fit all pages into pager
var maxPageNumbersToDisplay = options.MaximumPageNumbersToDisplay.Value;
firstPageToDisplay = list.PageNumber - maxPageNumbersToDisplay / 2;
if (firstPageToDisplay < 1)
firstPageToDisplay = 1;
pageNumbersToDisplay = maxPageNumbersToDisplay;
lastPageToDisplay = firstPageToDisplay + pageNumbersToDisplay - 1;
if (lastPageToDisplay > list.PageCount)
firstPageToDisplay = list.PageCount - maxPageNumbersToDisplay + 1;
}
//first
if (options.DisplayLinkToFirstPage == PagedListDisplayMode.Always || (options.DisplayLinkToFirstPage == PagedListDisplayMode.IfNeeded && firstPageToDisplay > 1))
listItemLinks.Add(First(list, generatePageUrl, options));
//previous
if (options.DisplayLinkToPreviousPage == PagedListDisplayMode.Always || (options.DisplayLinkToPreviousPage == PagedListDisplayMode.IfNeeded && !list.IsFirstPage))
listItemLinks.Add(Previous(list, generatePageUrl, options));
//text
if (options.DisplayPageCountAndCurrentLocation)
listItemLinks.Add(PageCountAndLocationText(list, options));
//text
if (options.DisplayItemSliceAndTotal)
listItemLinks.Add(ItemSliceAndTotalText(list, options));
//page
if (options.DisplayLinkToIndividualPages)
{
//if there are previous page numbers not displayed, show an ellipsis
if (options.DisplayEllipsesWhenNotShowingAllPageNumbers && firstPageToDisplay > 1)
listItemLinks.Add(Ellipses(options));
foreach (var i in Enumerable.Range(firstPageToDisplay, pageNumbersToDisplay))
{
//show delimiter between page numbers
if (i > firstPageToDisplay && !string.IsNullOrWhiteSpace(options.DelimiterBetweenPageNumbers))
listItemLinks.Add(WrapInListItem(options.DelimiterBetweenPageNumbers));
//show page number link
listItemLinks.Add(Page(i, list, generatePageUrl, options));
}
//if there are subsequent page numbers not displayed, show an ellipsis
if (options.DisplayEllipsesWhenNotShowingAllPageNumbers && (firstPageToDisplay + pageNumbersToDisplay - 1) < list.PageCount)
listItemLinks.Add(Ellipses(options));
}
//next
if (options.DisplayLinkToNextPage == PagedListDisplayMode.Always || (options.DisplayLinkToNextPage == PagedListDisplayMode.IfNeeded && !list.IsLastPage))
listItemLinks.Add(Next(list, generatePageUrl, options));
//last
if (options.DisplayLinkToLastPage == PagedListDisplayMode.Always || (options.DisplayLinkToLastPage == PagedListDisplayMode.IfNeeded && lastPageToDisplay < list.PageCount))
listItemLinks.Add(Last(list, generatePageUrl, options));
if (listItemLinks.Any())
{
//append class to first item in list?
if (!string.IsNullOrWhiteSpace(options.ClassToApplyToFirstListItemInPager))
listItemLinks.First().AddCssClass(options.ClassToApplyToFirstListItemInPager);
//append class to last item in list?
if (!string.IsNullOrWhiteSpace(options.ClassToApplyToLastListItemInPager))
listItemLinks.Last().AddCssClass(options.ClassToApplyToLastListItemInPager);
//append classes to all list item links
foreach (var li in listItemLinks)
foreach (var c in options.LiElementClasses ?? Enumerable.Empty<string>())
li.AddCssClass(c);
}
//collapse all of the list items into one big string
var listItemLinksString = listItemLinks.Aggregate(
new StringBuilder(),
(sb, listItem) => sb.Append(TagBuilderToString(listItem)),
sb => sb.ToString()
);
var ul = new TagBuilder("ul");
AppendHtml(ul, listItemLinksString);
foreach (var c in options.UlElementClasses ?? Enumerable.Empty<string>())
ul.AddCssClass(c);
if (options.UlElementattributes != null)
{
foreach (var c in options.UlElementattributes)
ul.MergeAttribute(c.Key, c.Value);
}
var outerDiv = new TagBuilder("div");
foreach (var c in options.ContainerDivClasses ?? Enumerable.Empty<string>())
outerDiv.AddCssClass(c);
AppendHtml(outerDiv, TagBuilderToString(ul));
return new HtmlString(TagBuilderToString(outerDiv));
}
private static TagBuilder Ellipses(PagedListRenderOptions options)
{
var a = new TagBuilder("a");
AppendHtml(a, options.EllipsesFormat);
return WrapInListItem(a, options, options.EllipsesElementClass, "disabled");
}
private static TagBuilder ItemSliceAndTotalText(IPagedList list, PagedListRenderOptions options)
{
var text = new TagBuilder("a");
SetInnerText(text, string.Format(options.ItemSliceAndTotalFormat, list.FirstItemOnPage, list.LastItemOnPage, list.TotalItemCount));
return WrapInListItem(text, options, "PagedList-pageCountAndLocation", "disabled");
}
private static TagBuilder PageCountAndLocationText(IPagedList list, PagedListRenderOptions options)
{
var text = new TagBuilder("a");
SetInnerText(text, string.Format(options.PageCountAndCurrentLocationFormat, list.PageNumber, list.PageCount));
return WrapInListItem(text, options, "PagedList-pageCountAndLocation", "disabled");
}
private static TagBuilder Next(IPagedList list, Func<int, string> generatePageUrl, PagedListRenderOptions options)
{
var targetPageNumber = list.PageNumber + 1;
var next = new TagBuilder("a");
AppendHtml(next, string.Format(options.LinkToNextPageFormat, targetPageNumber));
next.Attributes["rel"] = "next";
foreach (var c in options.PageClasses ?? Enumerable.Empty<string>())
next.AddCssClass(c);
if (!list.HasNextPage)
return WrapInListItem(next, options, options.NextElementClass, "disabled");
next.Attributes["href"] = generatePageUrl(targetPageNumber);
return WrapInListItem(next, options, options.NextElementClass);
}
/// <summary>
/// Enables ASP.NET MVC's unobtrusive AJAX feature. An XHR request will retrieve HTML from the clicked page and replace the innerHtml of the provided element ID.
/// </summary>
/// <param name="options">The preferred Html.PagedList(...) style options.</param>
/// <param name="ajaxOptions">The ajax options that will put into the link</param>
/// <returns>The PagedListRenderOptions value passed in, with unobtrusive AJAX attributes added to the page links.</returns>
public static PagedListRenderOptions EnableUnobtrusiveAjaxReplacing(PagedListRenderOptions options, AjaxOptions ajaxOptions)
{
options.FunctionToTransformEachPageLink = (liTagBuilder, aTagBuilder) =>
{
var liClass = liTagBuilder.Attributes.ContainsKey("class") ? liTagBuilder.Attributes["class"] ?? "" : "";
if (ajaxOptions != null && !liClass.Contains("disabled") && !liClass.Contains("active"))
{
foreach (var ajaxOption in ajaxOptions.ToUnobtrusiveHtmlAttributes())
aTagBuilder.Attributes.Add(ajaxOption.Key, ajaxOption.Value.ToString());
}
liTagBuilder.InnerHtml = aTagBuilder.ToString();
return liTagBuilder;
};
return options;
}
